Don't Have Spark

[Phillip Gwin]

I am hoping someone has a suggestion that I haven't thought of. I test drove my 88 around the pasture, the transmission was slipping, I shut it off to check out the vital fluids, and the transmission fluid was low. The next day I bought fluid, and added it. It has no spark now. I have checked, and it has power on the yellow wire, and the black wire is grounded. Nothing makes sense to have gone out with no warning. I hope some one has an idea I haven't thought of.

[Ωhm]

Do Cruisers tip for CPS output voltage (AC). Make sure your meter is set to VAC.

http://cruiser54.com/?p=50

[Phillip Gwin]

Thank you, I will try this tomorrow.

[75sv1]

I am presently working on a 2000 XJ. It would crank over etc. Everything but run. It did have issues with the front wipers. I did check with NOID lights on the injector plugs. They would not light, till I stopped cranking. I did try starter fluid. That did not help. I did try and trace voltage with some but not enough success. A friend suggested it might be the ignition relay, at the key. I replaced it and not it runs. 

 

Edit: Should be now it runs. I did check the coil(s) with an Ohm meter, as AZ describes and the Factory manual. I will be doing the Viper Coil upgrade at some point. Sort of want to see how that works out. Also, I will be swapping in an older head. So, the Viper Coil upgrade would simplify things. 

[AZJeff]

8 hours ago, 75sv1 said:

I am presently working on a 2000 XJ. It would crank over etc. Everything but run. It did have issues with the front wipers. I did check with NOID lights on the injector plugs. They would not light, till I stopped cranking. I did try starter fluid. That did not help. I did try and trace voltage with some but not enough success. A friend suggested it might be the ignition relay, at the key. I replaced it and not it runs. 

You can pull the coil rail and stick a plug into one of the rubber sockets (hold it in with some tape) and then ground the end of the plug.  If you see no spark there, then it's time to check the coil pack itself.   (There are actually THREE coils in the pack, by the way.)

 

The coil receives 12VDC whenever the key is "on", and the PCM controls the firing of the coils by grounding the lead from a given coil via a "drain" wire that goes to the PCM.   Because of this, there are 4 primary wires that go to the coil rail: 

---The dark green with orange tracer wire is the 12V feed from fuse #18 in the power distribution center.

---The gray wire is the "drain" for coil #1, and goes to pin 7 on connector C1 on the PCM

---The dark blue with tan tracer wire is the "drain" for coil #2, and goes to pin 9 on connector C2 on the PCM

---The red with a yellow tracer is the "drain for coil #3, and goes to pin 1 on connector C1 on the PCM

 

If you measure between the 12V feed pin on the coil pack to any of the other "drain" wires, the impedance should be 0.71 to 0.88 ohms.

[Warren Mohler]

12 hours ago, 75sv1 said:

I am presently working on a 2000 XJ. It would crank over etc. Everything but run. It did have issues with the front wipers. I did check with NOID lights on the injector plugs. They would not light, till I stopped cranking. I did try starter fluid. That did not help. I did try and trace voltage with some but not enough success. A friend suggested it might be the ignition relay, at the key. I replaced it and not it runs. 

 

Edit: Should be now it runs. I did check the coil(s) with an Ohm meter, as AZ describes and the Factory manual. I will be doing the Viper Coil upgrade at some point. Sort of want to see how that works out. Also, I will be swapping in an older head. So, the Viper Coil upgrade would simplify things. 

before you get too far into this inspect center connector of ECU to see if full of motor oil I have seen this in three XJ's, if its full of oil clean with brake clean and blow dry and replace oil sender recheck ECU connector after several weeks for oil, it will take a while for oil to stop seeping from plug

[75sv1]

OK, my XJ is running. I wanted to let the OP know that the ignition key and its electronics can be an issue. I am not sure of the older style of electronics for that. Also, as has been pointed out, ignition coils do go bad. I had one that was intermittent on a 78 Gremlin. 

[AZJeff]

On 11/4/2019 at 7:28 PM, Warren Mohler said:

before you get too far into this inspect center connector of ECU to see if full of motor oil I have seen this in three XJ's, if its full of oil clean with brake clean and blow dry and replace oil sender recheck ECU connector after several weeks for oil, it will take a while for oil to stop seeping from plug

The PCM on a 2000 XJ is located over by the air filter and is sandwiched between the air filter and the inside fender wall.  How is just the center connector (“C2”) going to get oil contamination?  In fact, how are ANY of the 3 going to get oil in them?

[Warren Mohler]

14 hours ago, AZJeff said:

The PCM on a 2000 XJ is located over by the air filter and is sandwiched between the air filter and the inside fender wall.  How is just the center connector (“C2”) going to get oil contamination?  In fact, how are ANY of the 3 going to get oil in them?

the oil pressure sender has a sealed connector when the sender starts leaking oil past the terminals it has nowhere to go but to migrate up the wires inside the  insulation, it will travel the whole way to the ECU which also has a sealed connection and accumulates till it causes a problem, my 99 XJ shut off one day on a steep hill with no pull off, I did a visual inspection and saw nothing wrong so did a wiggle of plugs starting at ECU, it fired right up with CEL on it had three odd codes set that were not even listed on charts all to do with communication with trans controller so once I was home the first place I went to was ECU, center plug was FULL of motor oil. I cleaned with brake clean and blew dry and had no problem after, about a month later rechecked and there was a small amount of oil there, so even after replacing sender it still took a while for oil to stop seeping from plug, since then I have seen this same  thing happen to two other XJ's, so now every time I see something odd this is the first place I go to save lots of diagnostic time. I am sure it has happened to others as  well.

[AZJeff]

8 hours ago, Warren Mohler said:

the oil pressure sender has a sealed connector when the sender starts leaking oil past the terminals it has nowhere to go but to migrate up the wires inside the  insulation, it will travel the whole way to the ECU which also has a sealed connection and accumulates till it causes a problem, my 99 XJ shut off one day on a steep hill with no pull off, I did a visual inspection and saw nothing wrong so did a wiggle of plugs starting at ECU, it fired right up with CEL on it had three odd codes set that were not even listed on charts all to do with communication with trans controller so once I was home the first place I went to was ECU, center plug was FULL of motor oil. I cleaned with brake clean and blew dry and had no problem after, about a month later rechecked and there was a small amount of oil there, so even after replacing sender it still took a while for oil to stop seeping from plug, since then I have seen this same  thing happen to two other XJ's, so now every time I see something odd this is the first place I go to save lots of diagnostic time. I am sure it has happened to others as  well.

You must have a different connector than I have/had.   On my 2000XJ, and my MJ that sports a 2001XJ engine/PCM, the connector is NOT a hermitic seal.  If oil leads out of the sender, it will weep out around the connector body where it slides over the plug half on the sender.